Clot detection based on signal-time history diagnostics

Abstract

The present disclosure provides a sensor system that includes a blood access device, a flow controller, and an analyte sensor. The system is configured to flush or draw a volume of fluid through the blood access device at least once; determine a signal-time history corresponding to signals received from the sensor; determine a duration of a portion of the signal-time history; determine whether the duration is greater than a predetermined threshold value; and detect the occlusion in the blood access device when the duration is greater than the predetermined threshold value.

What is claimed is: 
     
         1 . A system for detecting an occlusion in a blood access device, the system comprising:
 a blood access device in fluid communication with a calibrant solution source and a circulatory system of a patient;   a flow controller configured to sequentially draw blood from the circulatory system and flush fluid from the calibrant solution source through the blood access device, the sequential draw and flush defining a draw and flush cycle;   a sensor coupled to the blood access device and configured to generate one or more portions of a signal-time history associated with the draw and flush cycle;   a memory;   a processor; and   a computing module, stored in the memory, executable by the processor, and configured to cause the processor to:
 operate the flow controller to sequentially draw blood and flush fluid through the blood access device; 
 determine the signal-time history for the draw and flush cycle from the sensor; 
 determine a time duration of a predetermined portion of the signal-time history associated with the draw and flush cycle; 
 determine whether the time duration is greater than a predetermined threshold value; and 
 detect an occlusion in the blood access device when the time duration of the signal-time history is greater than the predetermined threshold value. 
   
     
     
         2 . The system of  claim 1 , wherein the sensor is a glucose sensor. 
     
     
         3 . The system of  claim 1 , further comprising halting display of information on a display when the occlusion is detected. 
     
     
         4 . The system of  claim 1 , wherein the predetermined threshold value is determined based on a standard signal-time history analyzed when an occlusion is not present. 
     
     
         5 . A method for detecting an occlusion in a blood access device, the method comprising:
 providing a blood access device in fluid communication with a calibrant solution source and a circulatory system of a patient;   providing a flow controller configured to sequentially draw blood from the circulatory system and flush fluid from the calibrant solution source through the blood access device, the sequential draw and flush defining a draw and flush cycle;   providing a sensor coupled to the blood access device and configured to generate one or more portions of a signal-time history associated with the draw and flush cycle; and   providing a processor for executing computer program code stored in a non-transitory computer-readable medium to cause the processor to:
 operate the flow controller to sequentially draw blood and flush fluid through the blood access device; 
 determine the signal-time history for the draw and flush cycle from the sensor; 
 determine a time duration of a predetermined portion of the signal-time history associated with the draw and flush cycle; 
 determine whether the time duration is greater than a predetermined threshold value; and 
 detect an occlusion in the blood access device when the time duration of the signal-time history is greater than the predetermined threshold value. 
   
     
     
         6 . The method of  claim 5 , wherein the sensor is a glucose sensor. 
     
     
         7 . The method of  claim 5 , further comprising halting display of information on a display when the occlusion is detected. 
     
     
         8 . The method of  claim 5 , wherein the predetermined threshold value is determined based on a standard signal-time history analyzed when an occlusion is not present. 
     
     
         9 . A computer program product for detecting an occlusion in a blood access device, the computer program product comprising:
 a non-transitory computer-readable medium comprising a set of codes for causing a computer to:
 operate a flow controller to sequentially draw blood and flush fluid through a blood access device, wherein the blood access device is in fluid communication with a calibrant solution source and a circulatory system of a patient; 
 determine a signal-time history for the draw and flush cycle from a sensor, wherein the sensor is coupled to the blood access device; 
 determine a time duration of a predetermined portion of the signal-time history associated with the draw and flush cycle; 
 determine whether the time duration is greater than a predetermined threshold value; and 
 detect an occlusion in the blood access device when the time duration of the signal-time history is greater than the predetermined threshold value. 
   
     
     
         10 . The computer program product of  claim 9 , wherein the sensor is a glucose sensor. 
     
     
         11 . The computer program product of  claim 9 , further comprising halting display of information on a display when the occlusion is detected. 
     
     
         12 . The computer program product of  claim 9 , wherein the predetermined threshold value is determined based on a standard signal-time history analyzed when an occlusion is not present.